College of Life Sciences, Dezhou University, 566 University Road, Dezhou, 253023, Shandong Province, China.
Sci Rep. 2024 May 8;14(1):10586. doi: 10.1038/s41598-024-60848-3.
Carotenoids play essential roles in plant growth and development and provide plants with a tolerance to a series of abiotic stresses. In this study, the function and biological significance of lycopene β-cyclase, lycopene ε-cyclase, and β-carotene hydroxylase, which are responsible for the modification of the tetraterpene skeleton procedure, were isolated from Lycium chinense and analyzed. The overexpression of lycopene β-cyclase, lycopene ε-cyclase, and β-carotene hydroxylase promoted the accumulation of total carotenoids and photosynthesis enhancement, reactive oxygen species scavenging activity, and proline content of tobacco seedlings after exposure to the salt stress. Furthermore, the expression of the carotenoid biosynthesis genes and stress-related genes (ascorbate peroxidase, catalase, peroxidase, superoxide dismutase, and pyrroline-5-carboxylate reductase) were detected and showed increased gene expression level, which were strongly associated with the carotenoid content and reactive oxygen species scavenging activity. After exposure to salt stress, the endogenous abscisic acid content was significantly increased and much higher than those in control plants. This research contributes to the development of new breeding aimed at obtaining stronger salt tolerance plants with increased total carotenoids and vitamin A content.
类胡萝卜素在植物的生长和发育中起着重要作用，并为植物提供了一系列抗非生物胁迫的能力。本研究从枸杞中分离出负责四萜骨架修饰过程的番茄红素 β-环化酶、番茄红素 ε-环化酶和 β-胡萝卜素羟化酶，并对其功能和生物学意义进行了分析。过量表达番茄红素 β-环化酶、番茄红素 ε-环化酶和 β-胡萝卜素羟化酶可以促进烟草幼苗在盐胁迫下总类胡萝卜素的积累和光合作用的增强，以及活性氧的清除活性和脯氨酸含量的增加。此外，还检测到类胡萝卜素生物合成基因和应激相关基因（抗坏血酸过氧化物酶、过氧化氢酶、过氧化物酶、超氧化物歧化酶和吡咯啉-5-羧酸还原酶）的表达，并且表现出更高的基因表达水平，这与类胡萝卜素含量和活性氧清除活性密切相关。在盐胁迫下，内源脱落酸含量显著增加，明显高于对照植株。这项研究有助于开发新的育种方法，获得具有更高总类胡萝卜素和维生素 A 含量、更强耐盐性的植物。
